app/gemini_client.py

from google.generativeai.embedding import embed_content
from google.generativeai.client import configure
from google.generativeai.generative_models import GenerativeModel
from loguru import logger
from .request_limit_manager import RequestLimitManager
from typing import List, Optional

class GeminiClient:
    def __init__(self):
        self.limit_manager = RequestLimitManager("gemini")
        self._cached_model = None
        self._cached_key = None
        self._cached_model_instance = None

    def _get_model_instance(self, key: str, model: str):
        """
        Cache model instance để tránh recreate mỗi lần.
        """
        if (self._cached_key == key and 
            self._cached_model == model and 
            self._cached_model_instance is not None):
            return self._cached_model_instance
        
        # Configure và tạo model instance mới
        configure(api_key=key)
        self._cached_model_instance = GenerativeModel(model)
        self._cached_key = key
        self._cached_model = model
        
        logger.info(f"[GEMINI] Created new model instance for key={key[:5]}...{key[-5:]} model={model}")
        return self._cached_model_instance

    def _clear_cache_if_needed(self, new_key: str, new_model: str):
        """
        Chỉ clear cache khi key/model thực sự thay đổi.
        """
        if (self._cached_key != new_key or self._cached_model != new_model):
            logger.info(f"[GEMINI] Clearing cache due to key/model change: {self._cached_key}->{new_key}, {self._cached_model}->{new_model}")
            self._cached_model_instance = None
            self._cached_key = None
            self._cached_model = None

    def generate_text(self, prompt: str, **kwargs) -> str:
        last_error = None
        max_retries = 3
        
        for attempt in range(max_retries):
            try:
                # Lấy current key/model từ manager
                key, model = self.limit_manager.get_current_key_model()
                
                # Sử dụng cached model instance
                _model = self._get_model_instance(key, model)
                
                response = _model.generate_content(prompt, **kwargs)
                self.limit_manager.log_request(key, model, success=True)
                
                if hasattr(response, 'usage_metadata'):
                    logger.info(f"[GEMINI][USAGE] Prompt Token Count: {response.usage_metadata.prompt_token_count} - Candidate Token Count: {response.usage_metadata.candidates_token_count} - Total Token Count: {response.usage_metadata.total_token_count}")
                
                if hasattr(response, 'text'):
                    logger.info(f"[GEMINI][TEXT_RESPONSE] {response.text}")
                    return response.text
                elif hasattr(response, 'candidates') and response.candidates:
                    logger.info(f"[GEMINI][CANDIDATES_RESPONSE] {response.candidates[0].content.parts[0].text}")
                    return response.candidates[0].content.parts[0].text
                
                logger.info(f"[GEMINI][RAW_RESPONSE] {response}")
                return str(response)
                
            except Exception as e:
                import re
                msg = str(e)
                if "429" in msg or "rate limit" in msg.lower():
                    retry_delay = 60
                    m = re.search(r'retry_delay.*?seconds: (\d+)', msg)
                    if m:
                        retry_delay = int(m.group(1))
                    
                    # Log failure với key/model thực tế đang được sử dụng
                    self.limit_manager.log_request(key, model, success=False, retry_delay=retry_delay)
                    
                    # Chỉ clear cache nếu key/model thay đổi
                    # Không clear cache ngay lập tức để tránh recreate không cần thiết
                    
                    logger.warning(f"[GEMINI] Rate limit hit, will retry with new key/model (attempt {attempt + 1}/{max_retries})")
                    last_error = e
                    continue
                else:
                    # Lỗi khác không phải rate limit
                    logger.error(f"[GEMINI] Error generating text: {e}")
                    last_error = e
                    break
        
        raise last_error or RuntimeError("No available Gemini API key/model")

    def count_tokens(self, prompt: str) -> int:
        try:
            key, model = self.limit_manager.get_current_key_model()
            _model = self._get_model_instance(key, model)
            return _model.count_tokens(prompt).total_tokens
        except Exception as e:
            logger.error(f"[GEMINI] Error counting tokens: {e}")
            return 0

    def create_embedding(self, text: str, model: Optional[str] = None) -> list:
        last_error = None
        max_retries = 3
        
        for attempt in range(max_retries):
            try:
                key, default_model = self.limit_manager.get_current_key_model()
                
                # Ưu tiên model được truyền vào parameter, chỉ fallback về default_model nếu không có
                use_model = model if model and model.strip() else default_model
                
                if not use_model:
                    raise ValueError("No model specified for embedding")
                
                logger.info(f"[GEMINI][EMBEDDING] Using model={use_model} (requested={model}, default={default_model})")
                
                configure(api_key=key)
                response = embed_content(
                    model=use_model,
                    content=text,
                    task_type="retrieval_query"
                )
                
                self.limit_manager.log_request(key, use_model, success=True)
                logger.info(f"[GEMINI][EMBEDDING][RAW_RESPONSE] {response['embedding'][:10]} ..... {response['embedding'][-10:]}")
                return response['embedding']
                
            except Exception as e:
                import re
                msg = str(e)
                if "429" in msg or "rate limit" in msg.lower():
                    retry_delay = 60
                    m_retry = re.search(r'retry_delay.*?seconds: (\d+)', msg)
                    if m_retry:
                        retry_delay = int(m_retry.group(1))
                    
                    # Log failure và trigger scan cho key/model mới
                    self.limit_manager.log_request(key, use_model, success=False, retry_delay=retry_delay)
                    
                    logger.warning(f"[GEMINI] Rate limit hit in embedding, will retry with new key/model (attempt {attempt + 1}/{max_retries})")
                    last_error = e
                    continue
                else:
                    logger.error(f"[GEMINI] Error creating embedding: {e}")
                    last_error = e
                    break
        
        raise last_error or RuntimeError("No available Gemini API key/model")